author
b. 1869
A Dutch historian whose surviving work points to a strong interest in early modern maritime history and the Dutch presence in the Philippines. His best-known book grew out of academic research completed at the University of Amsterdam in the late 1890s.
by Dirk Abraham Sloos
Dirk Abraham Sloos was a Dutch scholar born in 1869. The clearest confirmed record available here comes from the University of Amsterdam's Album Academicum, which lists him as D.A. Sloos and shows that he completed a doctorate in Dutch literature on June 21, 1898.
His dissertation was De Nederlanders in de Philippijnsche wateren vóór 1626, a study of Dutch activity in Philippine waters before 1626. That work is also preserved by Project Gutenberg, where he is credited as "Sloos, Dirk Abraham, 1869-," suggesting that his historical writing has remained accessible long after its original publication.
Beyond those academic and bibliographic details, I couldn't confirm much more about his personal life from reliable sources in this conversation, so this overview keeps to the facts that are clearly supported.